1. Field of the Invention
This invention relates to a mower adapted to be moved by a motor vehicle and powered by a power source. More specifically, the invention relates to a mower of the type having a group of working elements extending, during work, crosswise to a direction of travel of the motor vehicle (the direction of advance at work).
2. Description of the Prior Art
A pulled mower comprising a frame which extends crosswise to the direction of advance at work is known in the prior art. At each of its ends, this frame is equipped with a wheel; by these wheels, it rests and rolls on the ground. It is provided to equip this frame, in its median part, with a tongue which makes it possible to connect the mower to a tractor.
The frame supports a group of working elements which comprises two mowing and conditioning mechanisms. As viewed from the top, the two mowing and conditioning mechanisms form between one another an obtuse angle, open toward the rear. Each mowing and conditioning mechanism comprises a cutting bar section equipped with cutting elements, and a carrying structure to which the cutting bar section is connected. The latter comprises, at each of its ends, a rotor rotating around an axis directed upward. The carrying structure comprises two carrying elements which support the cutting bar section by going through the upper part of the corresponding rotors. Each mowing and conditioning mechanism also comprises a hydraulic motor extending above its end which is adjacent to the other mowing and conditioning mechanism. The two hydraulic motors are coupled to one another by a universal joint telescopic shaft, so that the movement of rotation of the cutting elements of one of the mowing and conditioning mechanisms is synchronous with the movement of rotation of the cutting elements of the other mowing and conditioning mechanism.
The two mowing and conditioning mechanisms are connected to one another, on the one hand, by a coupling ball joint extending, at least partly, under the cutting plane of the cutting elements and, on the other hand, by a common carrying structure. This common carrying structure consists of a beam extending higher than the mowing and conditioning mechanisms. Each mowing and conditioning mechanism is connected to a corresponding end of the beam by a guide yoke which makes it possible for the mowing and conditioning mechanism, on the one hand, to pivot around an axis extending approximately in the direction of advance at work and, on the other hand, to be displaced crosswise to said direction of advance at work.
The group of working elements, thus formed, comprises yokes used in the hooking of connecting rods forming a deformable parallelogram and by which said group of working elements is suspended from the frame.
The carrying structure of the group of working elements of this known mower is, because the two mowing and conditioning mechanisms have a certain number of degrees of freedom relative to one another, relatively complex and, consequently, relatively costly. Further, the many connections reduce the degree of reliability of the mower, because some of them can assume an intolerable play after a certain working period, while others can jam. Finally, the drive means of the group of working elements are no longer satisfactory.